Estes Odyssey #7235 Build, Part 9, Engine Mount

One of the 50/55 centering rings will need to be notched to allow engine hook flex.

I usually cut the notch with a single edge razor blade. You can simply press down on the blade and get a clean cut.

Notice the angle of the set blade. When cutting at this angle you can end up with sides that match the movement travel of the engine hook. 

Set the glued notched ring into the BT-55 body to hold the ends down as the glue dries.

I did cut off the finger tab . . . because I'm a big boy.

A sparse line of glue is rolled around the tube and the black retainer ring is slid into and over the glue until it rests against the top of the lower centering ring.

Fillets are then added.

The engine block ends up recessed inside the top of the mount when slid in against the top bend of the engine hook.